Network computers are also sometimes known as thin clients or dumb terminals. They provide access to a mainframe via a network and have little, if any, computing capacity of their own. Network computers provide remote access to a mainframe. They allow the user to input data or commands and receive output. The actual processing would be done on the mainframe. Capacity and speed: Network computers do not have any processing capacity of their own. Their speed will depend on i: the speed and capacity of the mainframe; ii: the speed of the network to which they are attached; iii: the number of users accessing the mainframe. Thus in periods of low demand, they will appear to function very quickly but would appear to slow down when the demand on the system is high. Cost: Network computers are relatively simple devices, hence they are fairly cheap. Typical users: These would generally be the end-users of the system such as managers, accountants, receptionists, accounts clerks and data capturers. Personal computers Personal computers or PCs for short are the type of computer that most users are familiar with. Because they are usually found on users desks, they are also sometimes called desktop computers. Operating systems such as Linux and Windows were designed specifically for personal computers. The same applies to the thousands of application packages that are available including OpenOffice.org and Microsoft Office. A typical PC consists of a main unit housing the CPU and disk drives, a VDU (Video Display Unit), a keyboard and a mouse. PCs are self contained computing systems that can be used for thousands of different tasks from creating a simple document to controlling a large industrial machine.

Capacity and speed: Because of the rapid advances in technology, the PC of today is more powerful than many mainframes of a few years ago. There is little sign that the rate of development is slowing down. Typically, a modern PC can store the equivalent of a few million pages of printed text and carry out millions of instructions in a second. What complicates the _ issue of speed in talking about PCs is the use of graphics. Most applications make intensive use of graphics. This demands enormous computing power. Computers, which would otherwise appear to be very fast, can appear to be quite slow because of the demands placed on them by the graphics used in an application. Other components, such as the graphics card, also play a role in the speed of a PC.